1. Field of the Invention
The present invention relates to a system and method for alignment of nanoparticles on a substrate, and in particular relates to a system and method for alignment of nanoparticles on a substrate by a polypeptide template.
2. Description of the Related Art
Nanoparticles (NPs) are widely used in optical-electrical devices, such as a plasmon waveguide, due to the unique optical, chemical, electronic and magnetic properties thereof. The plasmons in the visible regime have very limited propagation distance (on the order of tens of microns), and thus the propagation distance depends on the uniformity and alignment of the NPs. Up to now, the uniformity of the NPs is well controlled by current technology. However, alignment of nanoparticles is still a challenge.
Each of the NPs is arranged separately at a specific location by a scanning probe once. However, this method is time-consuming and needs expensive equipment. Some research using DNA as a template to align NPs has been disclosed. Because the DNA itself has negative charges and the substrate also has negative charges, there is a need to modify the substrate with some compounds, such as divalent ions (Ni2+ or Zn2+), before depositing the DNA templates on the substrate. However, the modification is tedious and the compounds modified on the substrate may reduce the propagation distance of the plasmon.
Accordingly, there is a need to develop a simple and cheap system and method for alignment of the NPs.